rMD17 data download fallback URL

src/schnetpack/datasets/rmd17.py

@@ -4,8 +4,8 @@
 import tempfile
 import tarfile
 from typing import List, Optional, Dict
-from urllib import request as request
-
+from urllib.request import Request, urlopen
+from urllib.error import URLError, HTTPError
 import numpy as np
 from ase import Atoms
 
@@ -194,13 +194,45 @@ def _download_data(
     ):
         logging.info("Downloading {} data".format(self.molecule))
         raw_path = os.path.join(tmpdir, "rmd17")
-        tar_path = os.path.join(tmpdir, "rmd17.tar.gz")
-        url = "https://figshare.com/ndownloader/files/23950376"
-        request.urlretrieve(url, tar_path)
+        tar_path = os.path.join(tmpdir, "rmd17.tar")
+        urls = [
+            "https://figshare.com/ndownloader/files/23950376",
+            "https://archive.materialscloud.org/records/pfffs-fff86/files/rmd17.tar.bz2?download=1",  # Fallback mirror
+        ]
+
+        downloaded = False
+        last_error = None
+
+        for u in urls:
+            try:
+                logging.info(f"Downloading from: {u}")
+                req = Request(u)
+                with urlopen(req, timeout=600) as resp, open(tar_path, "wb") as f:
+                    shutil.copyfileobj(resp, f)
+
+                size = os.path.getsize(tar_path)
+                ctype = (resp.headers.get("Content-Type") or "").lower()
+
+                if size == 0 or "text/html" in ctype:
+                    raise RuntimeError(
+                        f"Blocked or invalid download (size={size}, Content-Type={ctype})"
+                    )
+                logging.info(f"Download successful rMD17.")
+                downloaded = True
+                break
+
+            except (HTTPError, URLError, RuntimeError) as e:
+                last_error = e
+                logging.warning(f"Download failed from {u}: {e}")
+
+        if not downloaded:
+            raise RuntimeError(
+                "rMD17 download failed from both sources. " f"Error: {last_error}"
+            )
         logging.info("Done.")
 
         logging.info("Extracting data...")
-        tar = tarfile.open(tar_path)
+        tar = tarfile.open(tar_path, mode="r:*")
         tar.extract(
             path=raw_path, member=f"rmd17/npz_data/{self.datasets_dict[self.molecule]}"
         )